The present invention relates to an electromechanical contactor comprising a casing which houses a moving contact holder, the casing having a front portion equipped with connection terminals accessible through a front face, as well as a pushbutton which is connected to the contact holder and which is visible and accessible through the front face.
Contactors of this type are currently used for controlling low voltage electrical loads. The fixing of an electromechanical ancillary block having an auxiliary signalling function or another function which may be used in an automation plan, on the front of the casing of such a contactor, is frequently provided. The ancillary block has auxiliary contacts and a mobile component positioned in such a way that it cooperates with the push-button of the contactor unit in order to control the auxiliary contacts. The ancillary block may be attached to the contactor unit so as to be removable, usually by means of catches provided on the front face of the casing. It turns out that the state of the contactor may be viewed according to whether the push-button is protruding or recessed relatively to the front face; on the other hand the push-button is also used for manually testing the proper operation of the contactor""s mobile contact holder. Now it may be dangerous to carry out this test, which actually switches the load while the contactor is energized.
The object of the present invention is to prevent the push-button from being actuated manually, without affecting the possibility of viewing the state of the contactor, by taking advantage of the arrangements made on the front of the contactor""s casing for providing fixation of a front ancillary block or by taking advantage of similar arrangements.
According to the invention, the contactor""s casing provides on its front face and near the mobile pushbutton, fitting or snap-on catches, suitable for receiving an ancillary block which may be coupled with the push-button or suitable for mounting in the direction of the casing""s height; a cover is removably assembled on the front portion of the casing so as to hide the push-button, by being mounted on the front portion of the casing by means of assembling shapes cooperating with the catches. In this manner, the mounting of the cover makes use of the existing catches for assembling an ancillary block and/or facilitates straightforward assembly as for an ancillary block.
Advantageously, the cover may be a small plate which has a transparent portion located in front of the push-button and a hollowed-out portion edged with guide grooves for fitting and sliding onto the catches, in the direction of the contactor""s height; abutment shoulders provided at the end of the grooves preferably cooperate with abutment portions notably provided on the catches.
The cover preferably has a width substantially the same as that of the casing and a height such that the terminals remain accessible when it is assembled with the casing, while it provides on one long side a transverse surface adjacent to the terminals, making wiring easier.